Conventionally, various techniques have been proposed for efficiently accessing a memory such as an SDRAM. As one example of these techniques, a technique of alternately accessing banks by utilizing SDRAM bank access characteristics to thereby conceal overhead between commands has been proposed (for example, see Patent References 1 and 2).
Efficient access is also required in the case where data mapped on a memory is accessed in units of rectangular areas by commands including a plurality of row addresses, as in image processing of recent years.
Patent Reference 1: Japanese Unexamined Patent Application Publication No. 2001-256106
Patent Reference 2: U.S. Pat. No. 6,819,326